His efforts to raise money for his program were ________ because no one showed any intention to take

a cent out of their pockets.[ ]

A．in place  

B．in sight

C．in effect  

D．in vain

洁净室及洁净区空气中悬浮粒子洁净度等级共划分为（）等级。

A.6

B.9

C.10

D.12